scholarly journals The analysis and research on variable operating condition of exhaust steam and waste heat Cascade utilization system of air cooling heating unit

2019 ◽  
Vol 136 ◽  
pp. 01002
Author(s):  
Ning Zhao ◽  
Xiaoying Fan ◽  
Lite Ji ◽  
Ya-mi Chen
Keyword(s):  
Heat Pump ◽  
Waste Heat ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Air Cooling ◽  
Analysis Model ◽  
Exhaust Heat ◽  
Heat Pump Unit

The series and parallel exhaust heat cascade utilization system was adopted by the large direct air cooling heating units. On the one hand, this system could reduce the adverse impact on power generation; on the other hand, it could reduce the temperature difference of heat transfer through step by step heating, the irreversible loss could be reduced, and the energy utilization efficiency could be made higher. On the basis of grasping the design performance of exhaust steam utilization system and the variable operating performance of main equipment by analysing the data of typical operating conditions, the optimization analysis model of heat pump group and the whole plant was established by this paper. The performance of heat pump unit under variable operating conditions was analysed and calculated, the influence of different exhaust pressure and backwater temperature on the economy of the whole machine was analysed, and the optimal operation mode of the heat pump was obtained. Finally, the pumping and condensing ratio curves under different conditions of winter heating conditions were determined, which could guide the optimal operation of heat pump units. It also provided technical support and basis for deep peak regulation or flexible transformation of heating units.

Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

2007 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Energy System ◽  
Primary Energy ◽  
Economic Benefits ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energetic Efficiency ◽  
Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

Influence of Temperature Parameter Change on Lithium Bromide Absorption Heat Pump Performance

2013 ◽  
Vol 291-294 ◽  
pp. 1670-1674
Author(s):  
Biao Li ◽  
Jiang Fan
Keyword(s):  
Power Plant ◽  
Heat Pump ◽  
Waste Heat ◽  
Lithium Bromide ◽  
Optimal Operation ◽  
Pump System ◽  
Absorption Heat Pump ◽  
Heat Pump System ◽  
Heat Pump Unit ◽  
The Impact

It is the new way of the thermal power plant energy conservation to recycling plant circulating water waste heat for heating with the heat pump technology. The recovery of low temperature waste heat is the background. And lithium bromide absorption heat pump is the object of this study. The impact of changes in temperature parameters on the performance of heat pump unit is analyzed. As a theoretical basis for the design of the heat pump system and power plant heat pump unit’s optimal operation provide a reference. The result provides a theoretical reference for the optimal operation of the heat pump system design and power plant heat pump units.

Research on the Heating Plan of Recovering Condensing Heat of Power Plant by Water Source Heat Pump Unit

2012 ◽  
Vol 608-609 ◽  
pp. 1241-1245
Author(s):  
Wei Qiu ◽  
Li Zhang ◽  
Qing Rong liu
Keyword(s):  
Power Plant ◽  
Heat Pump ◽  
Air Conditioning ◽  
Waste Heat ◽  
Water Source ◽  
Pump Unit ◽  
Air Conditioning System ◽  
Central Heating ◽  
Heat Pump Unit ◽  
Direct Discharge

This paper analyses the energy consumption of water source heat pump, shows that the performance coefficient of water source heat pump unit is directly related to the temperature of water resources, and discusses the feasibility of central heating by recovering condensing heat of power plant using water source heat pump unit. It analyzes the energy saving benefit of water source heat pump unit is significant compared with traditional heating. Using the technology recovers waste heat of power plant, which can not only decrease the energy waste on the direct discharge of waste heat and water, but at the same time, it is a new air conditioning system without environmental pollution.

Organic Rankine Cycle for Waste Heat Recovery in a Hybrid Vehicle

2010 ◽  
Author(s):  
Quazi E. Hussain ◽  
David R. Brigham
Keyword(s):  
Fuel Economy ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Drive Cycle ◽  
Exhaust Heat

The Rankine cycle is used commercially to generate power in stationary power plants using water as the working fluid. For waste heat recovery applications, where the temperature is lower, water is typically replaced by a carefully selected organic fluid. This work is based on using the waste heat in an automobile to generate electricity using the Organic Rankine cycle (ORC) with R245fa (1, 1, 1, 3, 3 penta-fluoropropane) as the working fluid. The electricity thus generated can be used to drive the accessory load or charge the battery which in any case helps improve the fuel economy. A simple transient numerical model has been developed that is capable of capturing the main effects of this cycle. Results show that exhaust heat alone can generate enough electricity that is capable of bringing about an improvement to the fuel economy under transient drive cycle conditions. Power output during EPA Highway drive cycle is much higher than EPA City due to higher exhaust mass flow rate and temperature. Time needed to reach operating conditions or in other words, the warm-up time plays an important role in the overall drive cycle output. Performance is found to improve significantly when coolant waste heat is used in conjunction with the residual exhaust heat to pre-heat the liquid. A sizing study is also performed to keep the cost, weight, and packaging requirement down without sacrificing too much power. With careful selection of heat exchanger design parameters, it has been demonstrated that the backpressure on the engine can be actually lowered by cooling off the exhaust gas. This lower backpressure will further boost the fuel economy gained by the electricity produced by the Rankine bottoming cycle.

scholarly journals Impact of waste heat recovery systems on energy efficiency improvement of a heavy-duty diesel engine

2017 ◽  
Vol 38 (3) ◽  
pp. 63-75 ◽  
Author(s):  
Zheshu Ma ◽  
Hua Chen ◽  
Yong Zhang
Keyword(s):  
Energy Efficiency ◽  
Diesel Engine ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Reduction Factor ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Container Ship ◽  
Large Container

Abstract The increase of ship’s energy utilization efficiency and the reduction of greenhouse gas emissions have been high lightened in recent years and have become an increasingly important subject for ship designers and owners. The International Maritime Organization (IMO) is seeking measures to reduce the CO2 emissions from ships, and their proposed energy efficiency design index (EEDI) and energy efficiency operational indicator (EEOI) aim at ensuring that future vessels will be more efficient. Waste heat recovery can be employed not only to improve energy utilization efficiency but also to reduce greenhouse gas emissions. In this paper, a typical conceptual large container ship employing a low speed marine diesel engine as the main propulsion machinery is introduced and three possible types of waste heat recovery systems are designed. To calculate the EEDI and EEOI of the given large container ship, two software packages are developed. From the viewpoint of operation and maintenance, lowering the ship speed and improving container load rate can greatly reduce EEOI and further reduce total fuel consumption. Although the large container ship itself can reach the IMO requirements of EEDI at the first stage with a reduction factor 10% under the reference line value, the proposed waste heat recovery systems can improve the ship EEDI reduction factor to 20% under the reference line value.

scholarly journals Thermodynamic Analysis of Combined Cooling Heating and Power System with Absorption Heat Pump Based on Small Modular Lead-based Reactor

2021 ◽  
Vol 245 ◽  
pp. 01025
Author(s):  
Han Wang ◽  
Dali Yu ◽  
Chi Xu ◽  
Muhammad Salman Khan ◽  
Yunqing Bai
Keyword(s):  
Heat Pump ◽  
Thermodynamic Analysis ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Outlet Temperature ◽  
Pump System ◽  
Absorption Heat Pump ◽  
Remote Areas ◽  
Energy Demands ◽  
Combined Cooling

Small Modular Lead-based Reactor (SMLR) has generated great interest in academic research all around the world due to its good safety characteristics and relatively high core outlet temperature. In this paper, a Combined Cooling Heating and Power (CCHP) system with usage of absorption heat pump, which couples with a SMLR, was proposed to fulfill the energy demands in remote areas. Thermodynamic analysis was implemented to improve the performance of the CCHP system based on SMLR. To meet the remote areas’ energy needs, the main parameters and mass flow rate of a 35 MWth SMLR design were analyzed. The SMLR CCHP with absorption heat pump system can provide electric power 12.5MWe, heating 9.5MWh, and cooling 2.54MWc. The total energy utilization efficiency of the system can be 69.12 %. This work can provide a reference in the design and optimization of the CCHP system to meet the energy demands in the remote areas.

Heat exchanger design optimization for mitigation of diesel engine exhaust fouling

2020 ◽  
pp. 1-36
Author(s):  
Victor C. Aiello ◽  
Girish Kini ◽  
Marcel Staedter ◽  
Srinivas Garimella
Keyword(s):  
Design Optimization ◽  
Heat Pump ◽  
Waste Heat ◽  
Large Data ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Component Level ◽  
Pressure Drops ◽  
Single Tube ◽  
Wide Range

Abstract The design optimization of a diesel exhaust coupled heat and mass exchanger that drives a 2.71 kW cooling capacity absorption heat pump is presented in this study. Fouling layer thermal resistance and pressure drops from single-tube experiments are used to develop a thermodynamic, heat transfer, and pressure drop model for the exhaust coupled desorber. A parametric study is performed to select a desorber design that meets system performance while minimizing footprint. Experimental heat duties and pressure drops are within 10% and 3%, respectively, of the model predictions. Thus, large data sets from single-tube experiments with representative geometries are successful in accounting for fouling effects at the component level. Desorber design optimization based on this approach ensures continued heat pump performance after fouling. This study, along with the single tube experiments, presents a systematic approach to design exhaust-coupled heat exchangers while considering the effects of fouling. These results are applicable for a wide range of waste-heat recovery applications and this method can be extended to different geometries and operating conditions.

Compact Diesel Engine Waste-Heat Driven Ammonia-Water Absorption Heat Pump Modeling and Performance Maximization Strategies

2021 ◽  
pp. 1-28
Author(s):  
Christopher M. Keinath ◽  
Jared Delahanty ◽  
Srinivas Garimella ◽  
Michael A. Garrabrant
Keyword(s):  
Heat Exchanger ◽  
Water Absorption ◽  
Heat Pump ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Ammonia Water ◽  
Absorption Heat Pump ◽  
Wide Range

Abstract An investigation of the best ways to achieve optimal performance from a waste-heat-driven ammonia-water absorption heat pump over a wide range of operating conditions is presented. Waste-heat is recovered using an exhaust gas heat exchanger and delivered to the desorber by a heat transfer fluid loop. The absorber and condenser are hydronically coupled in parallel to an ambient heat exchanger for heat rejection. The evaporator provides chilled water for space-conditioning with a baseline cooling capacity of 2 kW. A detailed thermodynamics model is developed to simulate performance and develop strategies to achieve the best performance in both cooling and heating modes over a range of operating conditions. These parametric studies show that improved coefficients of performance can be achieved by adjusting the coupling fluid temperatures in the evaporator and the condenser/absorber as the ambient temperature varies. With the varying return temperatures, the system is able to provide the 2 kW design cooling capacity for a wide range of ambient temperatures.

Analysis of Exergy Utilization Efficiency of Combined Cooling Heating & Power on Gas Engine-Driven Heat Pump System

2010 ◽  
Vol 171-172 ◽  
pp. 350-353
Author(s):  
Lin Qiu ◽  
Qiang Li
Keyword(s):  
Heat Pump ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Thermal System ◽  
Pump System ◽  
Heat Pump System ◽  
Gas Engine ◽  
Operational Models ◽  
Combined Cooling

The exergy utilization efficiency is the better reasonable to measure quantity and quality of thermal system then energy utilization efficiency .This text analyzed the exergy utilization efficiency of gas engine-driven heat pump(GEHP) at different combined supply energy modes. . Simulation computes gives that the heat recover plays the important action for increases exergy utilization efficiency of GHP system, especially at combined heating and electricity operational models, and the rules of heat recollection ratio and heat recollection temperature to exergy utilization efficiency of CHCP system were provided.

The Experimental Study of New-Type Water-Cooling PV/T Collector

2011 ◽  
Vol 374-377 ◽  
pp. 242-247 ◽  
Author(s):  
Ning Jun Li ◽  
Zhen Hua Quan ◽  
Yao Hua Zhao ◽  
Na Na Guo
Keyword(s):  
Experimental Study ◽  
Waste Heat ◽  
Hot Water ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Total Efficiency ◽  
Forced Circulation ◽  
Electrical Efficiency ◽  
Pv Modules ◽  
T System

A new photovoltaic/thermal (PV/T) system based on the micro plate heat pipe is established in this paper, and the experimental study is conducted for nature convection, forced circulation cooling and common PV module. the experiment carried out on May showed that the highest temperature were 50°C and 52°C respectively for nature convection and forced circulation cooling module, the daily average electrical efficiency were relatively increased by 13.1% and 6.1% than common PV modules, the total efficiency ηo reached 54.2% and 50.3%, and the primary-energy saving rate were 73.1% and 68%.the result indicates that in the new PV/T system the temperature of the PV modules is reduced, the electrical efficiency is keeping at a high level, and the waste heat can be made good use to get hot water, therefore the solar energy utilization efficiency was raised greatly.

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